EP0136427A1 - Cutting device for bar-shaped material - Google Patents

Abstract

1. Apparatus for the cutting of heated bars (33, 57) of metal, in which arrangement the bars are transported by a first transport device (13) with constant feed adjacent one another as a bar column through a heating device (14) and, in the final section of the heating device before the cutting apparatus (42, 45, 51), are moved by a second transport device (18) with increased feed over the cutting edge and against a stop, and a sensor, arranged ahead of the cutting edge, detects the occurrence of a gap between two successive bars and is aligned with the transport path of the bars so that its sensing region is located at an interval of twice the section length (A) plus a minimum residual length (B) necessary for cutting the bars in front of the stop, and that following the sensor is a control device (50, 56) which delivers control signals for the further treatment of the bar residue as a function of the presence or absence or a bar section in the sensing region of the sensor and a repulsion device (35, 36) to repel back bar residues after cutting into the heating device, characterized in that a clamping device (43) maintains a bar (33) moved against the stop (32) in this cutting position and in that the second transport device (18), which is arranged in front of the sensing region (54) of the sensor, acts on the bars in the opposite direction of rotation and, in the presence of a contact point between two bars (33 and 57) in the region between the clamping device (43) and the second transport device (18), the unclamped bar moves back into the heating device and a gap is produced between the abutting bars (33 and 57) and the sensor detects this.

Description

The invention relates to a shearing device for heated rod-shaped material of finite length made of metallic material with a transport device upstream of the shearing device for forward and backward transport of the rods in the longitudinal direction of the rod, a stop downstream of the shearing device in the longitudinal direction of the rod to limit the transport movement of the rods, and a clamping device for holding the rods in their shear position, a device for removing the cut rod sections or residual ends from the shear position and a recoil device for retracting or pushing remaining bars after shearing into a heating device.

Shear devices of this type are used, in particular, to cut warm, rod-shaped material for further processing in a forging device. In order to avoid disturbances in the production process, it is necessary that the sheared rod sections always adhere to an exact desired length, which is due to the position of the Stop can be specified.

If a remaining end of the rod-shaped material is conveyed into the area of the shearing device, this must be separated from the production process. A residual end occurs when it can no longer be sheared safely, i.e. when its length is less than the length of a rod section plus a clamping length required for the shearing process.

For the detection and rejection of rod shears that can no longer be sheared, DE-AS 26-31 989 proposed to arrange a gripping device for the bar material behind the shearing device in the transport direction of the bars, which device exerts a tensile or compressive force on the bar material before shearing. If there is a remaining end, the gripping device transports it from the shear position and emits a signal to separate out the remaining end. However, if the rest of the bar can be sheared again, it is held in the shear position by a hold-down device.

However, this shaving device with gripping device is not suitable for shearing long bar sections. When long bar sections are sheared, the cycle time is so long because of the time required for forging that a return of the bar remnants is required after a bar section has been cut to length in the heating system in order to avoid excessive cooling of the bar remnants. Such a return transport is not provided for in the device according to DE-AS 26 31 989.

A system for shearing long bar sections can be found in the article "Induction heating and hot cutting system for forging blanks" in the ASEA magazine 1982, vol. 27, pages 15 to 20. This system provides for the return of the bar remnants. Residual detection is carried out by a positioning system with length measurement on the bars in the area before heating. However, this solution is very complex and requires additional expenditure in the area of the bar magazine. Furthermore, tracking of the bar position in the system with the aid of memories is necessary, which results in a high control effort.

The object of the invention is to design a shearing device of the type mentioned at the outset in such a way that when a rod section is cut to length, it is recognized whether the rest of the rod has a sufficient length in order to be able to shear again. For the shearing of long bar sections, an economical solution is to be given which allows the bar remnants to be returned to the heating device. The aforementioned disadvantages of known shear devices should be avoided.

According to the invention, this object is achieved in that, in a shearing device of the type mentioned at the outset, a sensor for scanning the rods is aligned with the transport path of the rods in such a way that its scanning range is at a distance of twice the section length plus the minimum remaining length required for shearing the rods before the stop lies, and that a control device is connected downstream of the sensor which, depending on the presence or absence of a rod section in the scanning range of the sensor, emits control signals for the further treatment of the remaining rod.

Compared to known devices, this solution requires little mechanical equipment and is therefore insensitive to wear. It avoids touch or damage to the rods and enables reliable operation with close tolerances. It is particularly suitable for operation with long cycle times, in which the bars would cool down too much without being pushed back into the heating area.

A light barrier with a light source (e.g. also laser) and photo receiver, an infrared light barrier, a reflection light scanner or a pneumatic device can preferably be provided as the sensor. A sensor system, for example, can be used as the reflection light scanner, which focuses infrared pulses emanating from a transmitter diode through a lens onto the scanning area and receives the radiation reflected by a rod through a light receiver. If there is no rod section in the scanning area, no reflected radiation is registered by the light receiver. A gas nozzle can be provided as a pneumatic device, which is directed onto the rod in the scanning area. The gas outflow or the gas pressure in the nozzle indicate whether there is a rod section in the scanning area.

The control device can advantageously be designed in such a way that it evaluates the switching time of the sensor in connection with the return speed of the rods and determines the length of the remaining rod. When using a timer in the control device, it can distinguish between short and long remnants. This is advantageous since it can be expedient to push longer residues back into the heating system, although they can no longer be sheared, and to separate short residues in any case. The control device with a timing element can effect a corresponding manipulation of the remaining pieces.

When there is a remaining end, the control device sends a control signal to the manipulator (device for removing the sheared rods) to separate the remaining end from the transport device. Furthermore, the control device influences the recoil device in such a way that if a remaining bar that can be sheared again is pushed back into the heating device. The control device can also act on the bar transport device in such a way that it carries the remainder of the bar back into the heating system.

An advantageous embodiment of the invention provides that the stop is adjustable in the longitudinal direction of the rod, and that a device is provided which couples a longitudinal displacement of the scanning range of the sensor with the adjustment of the stop, in such a way that the stop and the scanning range are the same Amount, however, be moved in the opposite direction. The stop position can be coupled to the sensor position, for example, by mechanical or electromotive means.

The invention, as well as further advantageous refinements and developments, are to be described and explained in more detail with reference to the drawing, in which several exemplary embodiments of the invention are shown.

• Fig. 1 eine schematische Darstellung einer Induktionserwärmungsanlage mit erfindungsgemäßer Warmschereinrichtung für Schmiederohlinge,
• Fig._.2 und 3 je eine erfindungsgemäße Abschereinrichtung in Seitenansicht bzw. Draufsicht und teilweise geschnitten und
• Fig. 4 ein Funktionsbild einer Lageverstelleinrichtung für den Abtastsensor.

Show it:

• 1 is a schematic representation of an induction heating system with inventive warm shear device for forging blanks,
• Fig _. 2 and 3 each have a shearing device according to the invention device in side view or top view and partially cut and
• Fig. 4 is a functional diagram of a position adjustment device for the scanning sensor.

The rods, not shown in FIG. 1, are removed from a magazine 11 and inserted into the infeed roller table 12. They are detected by a drive device 13 with a continuous feed and transported at a constant speed through a heating device 14. The heating device 14 contains a plurality of induction coils 15, optionally with individual electrical energy supply and power control, by means of which an optimal heating process can be achieved.

Before the rods are inserted into the driving device 13, the straightness of the rods is checked. Poles which are too strongly curved are automatically sorted out and placed in an outer magazine 16. The bars usually run against each other, i.e. without space, via the conveyor rollers 17 through the heating device 14. Following the conveyor rollers 17, the bars reach driving devices (transport devices) 18, which are equipped with rapid traverse and overload clutch for forward and backward transportation of the bars.

When a rod has reached the end of the heating device 14, it is moved by the driving devices 18 with increased feed against a stop 19 and held by a hold-down device. The driving devices 18 are now driven in the opposite direction of rotation and exert a pulling force on the rod lying in their area of influence for the return transport into the heating device 14. It is not possible to return the rod if it is in the area of influence of the driving devices lying rod is so long that it extends to the stop 19 itself. In this case, the overload clutches of the driving devices 18 take effect.

However, if two rods come together in the area between the stop 19 and the driving device 18, the second rod is moved back into the heating device 14 by the driving devices 18, while the first rod lying against the stop 19 is held by the hold-down device. This creates a gap between the rods, which is recognized by a sensor when there is a remaining end.

After shearing, the rod remnant is pushed back into the heating device 14 by a recoil 21, which can be pivoted onto the stop axis, so that it does not cool down. The sheared rod section 22 is fed by a manipulator to a forging device, not shown.

A sensor for scanning the rods, indicated by an arrow 23, is arranged at a distance of twice the section length A plus a minimum remaining length B required for shearing off the rods. The sensor is able to determine whether a bar section is in its scanning area. The sensor is connected downstream of a control device, not shown in Figure 1, depending vom.Vorhandensein or absence of a rod part _-. Emits portion in the sensing region of the sensor control signals for the further treatment of the remaining bar.

FIGS. 2 and 3 only show the area of the shaving device, FIG. 2 showing a side view and FIG. 3 showing a top view of the shaving device. In Fig. 3 the Schermes However, this is only indicated symbolically. Furthermore, Figures 2 and 3 differ in the choice of the sensor. Figure 2 shows a pneumatic device as a sensor, while in Figure 3 the sensor is designed as a light barrier.

Both FIG. 2 and FIG. 3 are a drive apparatus 30, a spool 31, a rod 33 moved against a length stop 32, a recoiler 36 which can be pivoted onto the stop axis 34 and can be actuated by a hydraulic cylinder 35, and a reject slide 37 (via which to short, too hot and too cold bar parts can be removed) and a switch 39 which can be actuated by a hydraulic cylinder 38 can be removed. The cylinder is shown rotated 90 ^0th

FIG. 2 also shows a support table 40 on which the rod 33 slides, a lower knife 42 which can be actuated by a hydraulic cylinder 41, a hold-down device 43 which can be actuated by a hydraulic cylinder and an upper knife 45 which can be actuated by a hydraulic cylinder 44. At a distance (from the stop 32 calculated) twice the section length A plus the minimum remaining length B (clamping length) required for shearing the rods, a nozzle 46 is directed onto the rod 33. The nozzle 46 represents the end of a pipe 47 under gas pressure. The pressure in the pipe 47 is built up by a pressure generator 48. A pressure meter 49, the signal of which is evaluated by a control device 50, measures the gas pressure in the tube 47. If the partial section of a rod 33 is located in front of the nozzle 46, the pressure in the tube 47 is higher than in the absence of a rod 33 in the nozzle area 5%. . In this way, the control device 50 determines whether or not there is a rod 33 in the region of the nozzle 46.

In Figure 3, the scissors 51 is only shown symbolically. At a distance of twice the section length A plus the minimum remaining length B required to shear off the rods, a light barrier consisting of a light source 52 and a radiation receiver 53 is arranged in front of the stop B. If the section of a rod is located in the scanning area 54 of the light barrier, the light beam between the radiation source 52 and the radiation receiver 53 is interrupted. The signal of the radiation receiver 53 is amplified by an amplifier 55 and passed on to a control device 56. The control device 56, depending on whether there is a shearable remaining bar in front of the shear plane 51 at the time the bar 33 is sheared off, gives control signals to the cylinder 35 of the recoil 36 (and, which has not been shown, to the swivel device of the recoil 36 Swinging into the stop axis 34) and the cylinder 38 of the switch 39 from control signals.

In the exemplary embodiment according to FIG. 3, a first rod 33 and a second rod 57 directly adjoining the first rod 33 lie in the transport path of the rods. The two rods 33, 57 touch at position 58. As can be seen from FIG first rod 33 only one rod section (rod section length A) can be obtained. The remaining piece, although it is still longer than a rod section length A, is too short to be sheared again, since the remainder remaining after deduction of a rod section length A falls below the required clamping length B and therefore it is no longer possible to securely clamp the remaining end.

• Eine Stange 33 wird durch die Treibapparate 30 gegen den Anschlag 32 gefahren und durch den Niederhalter 43 der Schere festgehalten. Danach reversieren die Treibapparate und ziehen eine Lücke zwischen der ersten am Anschlag 32 anliegenden Stange 33 und einer zweiten Stange, die im Einflußbereich der Treibapparate 30 liegt. Registriert der Sensor 46; 52, 53 diese Lücke, so bedeutet dies, daß die am Anschlag anliegende Stange kürzer ist als die doppelte Stangenabsehnittlänge A (Blocklänge) zuzüglich einer minimalen Reststücklänge B (Einspannlänge).

The criteria on the basis of which the control device 50, 56 recognizes residual ends and control signals for the further processing action of the remaining bars should be explained in the following using a functional sequence:

• A rod 33 is moved by the driving devices 30 against the stop 32 and held by the hold-down device 43 of the scissors. Thereafter, the driving devices reverse and draw a gap between the first rod 33 abutting the stop 32 and a second rod which lies in the area of influence of the driving devices 30. If the sensor 46 registers; 52, 53 this gap, this means that the bar abutting the stop is shorter than twice the length of the bar section A (block length) plus a minimum remaining piece length B (clamping length).

Simultaneously with the retraction of the second rod 57, a rod section of length A is cut by the scissors 42, 45; 51 cut off from the bar abutting the stop 32 and transported by a manipulator (not shown) from the area of the shears to the forming machine (e.g. forging press). Then the recoil 36 swings into the stop axis 34 and pushes the remaining rod back into the heating device 14.

Is the rod 33 deflected so far that the sensor 46; 52, 53 registers a gap when moving back the second rod 57 (release signal), this means that after the rod 33 has been cut off, the remainder of the rod is a remnant which cannot be sheared again because it is not of sufficient length to be held down by the hold-down device 43 having.

In the control unit 50, 56, a timer is integrated, which records the time between the start of the retraction and the release signal of the sensor 46; 52, 53 measures. If this time remains below an experimentally or theoretically determinable value, the remaining end is a "longer" remaining end. Time ever exceeds but a given value, it is a "short" remaining end.

If it is a "longer" residual end, the control device 50, 56 emits a control signal to the recoiler 36, which pushes the remaining end back into the heating device 14. Only at the next cycle the remaining end is sorted out and the reject slide 37 slides down. If, however, there is a "short" end of the remainder, the control device 50, 56 emits a control signal for immediate rejection of the remainder of the end to a device, not shown.

A device can be seen in FIG. 4, by means of which the position of a sensor 60 along the transport path of the rods is coupled to the position of the length stop 32 in such a way that the length stop 32 and the scanning area 54 of the sensor 60 are adjusted by the same amount, but in opposite directions Direction in the longitudinal direction of the rod can be shifted. For this purpose, the position of the length stop 32 is determined by a position sensor 61. The position sensor 61 emits a corresponding control signal to a slide 62 which can be moved along the transport path of the rods and on which the sensor 60 is mounted. The control is designed in such a way that a displacement of the length stop 32 by the amount a to the left causes a displacement of the sensor by the amount a but also to the right.

Claims (7)

1. shearing device for a heated rod-shaped material of finite length made of metallic material with a transport device upstream of the shearing device for forward and backward transport of the rods in the longitudinal direction of the rod, one stop downstream of the viewing device in the longitudinal direction of the rod to limit the transport movement of the rods, a clamping device for holding the rods in their shear position, a device for removing the sheared rod sections or residual ends from the shear position and a recoil device for retracting or pushing residual rods after shearing into a heating device, characterized. that a sensor for scanning the bars (33) is aligned with the transport path of the bars (33) such that its scanning area (54) is at a distance of twice the section length (A) plus the minimum remaining length (B. required for shearing the bars (33)) ) is in front of the length stop (32), and that a control device (50, 56) is connected downstream of the sensor, which, depending on the presence or absence of a rod section in the scanning area (54) of the sensor, emits control signals for the further treatment of the remaining rod. 2. Shaving device according to claim 1, characterized in that a light barrier with light source (52) and photoelectric receiver (53) is provided as a sensor for scanning the rods (33). 3. Shaving device according to claim 2, characterized in that the light barrier is an infrared light barrier. 4. Shaving device according to claim 1, characterized in that a reflection light sensor is provided as a sensor. 5. Shaving device according to claim 1, characterized in that a pneumatic device is provided as a sensor. 6. Shaving device according to one of claims 1 to 5, characterized in that the control device (56) evaluates the switching time of the sensor in connection with the return speed of the rods (33) and determines the length of a remaining end. 7. Shaving device according to one of claims 1 to 6, characterized in that the length stop (32) is adjustable in the longitudinal direction of the rod and that a device is provided which couples a longitudinal displacement of the scanning area (54) of the sensor with the adjustment of the length stop (32) , in such a way that the length stop (32) and the scanning area (54) are shifted by the same amount (a), but in the opposite direction.

Images